Shallow landslide mitigation through bio-inspired techniques in clay soils: The example of Penicillium chrysogenum

This research investigates the potential of using fungi to enhance the soil’s hydrological, physical, and mechanical properties in different stages. The hyphae generated by the selected fungi fill the voids within soil structures, in which they are leading to a decrease in porosity and improved soil strength. This study involves a novel natural-based solution with the cultivation of the fungi named Penicillium chrysogenum in three different kinds of Clayey soils to evaluate their effectiveness in soil treatment. In this research, Various experimental techniques were employed to analyze soil properties plus the impact of fungal activity. The Atterberg limit is used to determine the soil’s physical properties. For hydrological properties, Soil Water retention curves were determined by using the Hyprop device, WP4C machine, and LABROS software, and then the Wet Sieve apparatus for the aggregate stability and Water Drop Penetration time to determine the soil’s degree of repellency. Moreover, to obtain mechanical properties, Direct Shear and Oedometer tests were conducted to examine soil consistency and strength. Additionally, Scanning Electron Microscopy (SEM) was utilized to observe fungal growth within the soils. This study employed three different, novel methodologies for obtaining the soil water retention curves, Mixing (M), Surface (S), and Injection (I), to evaluate the effectiveness of fungi under different scenarios, and the results indicate significant variations in soil properties based on fungal treatment and application methods. Compared to untreated control samples, fungal-treated soils demonstrated enhanced strength and improved consistency. These findings underscore the transformative potential of fungal treatments in soil improvement and highlight the importance of tailored application methods for different clay soil types. This study contributes to the understanding of natural soil improvement techniques in areas where there is a risk of landslide and erosion are possible, which can be used, emphasizing the role of fungi in modifying soil characteristics. The integration of biological processes and advanced testing methods offers a promising avenue for sustainable geotechnical engineering applications.